This invention relates to blast protection structures and in particular to bags used to make blast protection walls and roadways.
A classic temporary blast protection wall is made of sandbags. Although sandbags are of proven value, they do have drawbacks. They are time consuming and not that easy to fill. They generally have to be filled at least a short distance away from where the wall is to be built, and hence have to be carried there after filling. Further, a suitable filling material is not always readily available, and once the need for the wall is over, emptying the bags and disposing of the filling material can be as problematic as filling them and building the wall in the first place.
An alternative that has been in more recent use, comprises tanks of water, built up like bricks. The tanks are generally of black or at least dark plastics material and are substantially rigid. They are fairly light when empty, and so courses of tanks can easily be placed one adjacent another to form a wall, and then filled in situ from a hose, using either a local water supply or a tanker. But they are bulky items to store and transport, and they cannot readily be made to nest together in a compact stack. They have to be closed vessels. Also, being opaque, they cannot be checked at a glance to see whether they are full or empty.